A virtual storage area network (VSAN) aggregates storage directly attached to servers (e.g., host computers) to create a distributed, shared storage system for a number of workloads (e.g., virtual machines) running on the servers. For example, each server may utilize an attached solid state drive as a cache and one or more hard disk drives as underlying storage. The cache may improve input/output (I/O) performance for some workloads e.g., as compared to operating outside of a VSAN. The I/O performance of other workloads, however, may not benefit from the cache. As a result, it is worthwhile to be selective in which workloads are run within a VSAN and/or the caching policies for the selected workloads. Additionally, the amount by which I/O performance is improved is dependent upon the amount of memory allocated for caching each workload. Collecting and analyzing I/O requests for a large number of workloads to determine an amount of memory to allocate, however, is costly in terms of time, storage, and processing resources.